Reagent reservoir for fluids

ABSTRACT

A reagent reservoir for fluids, including a storage chamber connected to a duct for conducting fluid out of, into and/or through the storage chamber. The duct includes a duct section delimited by a substrate and a film joined to the substrate. The duct is sealed and is openable at a predetermined breaking point by deflecting the film. The film also delimits the storage chamber and covers a recess in the substrate which forms the duct section. A sealing wall that seals the duct and is integrally joined to the substrate is placed in the recess. The predetermined breaking point is formed by a breakable joining region between the film and an edge portion of the sealing wall facing the film. The dimensions of a peripheral area of the sealing wall, which is formed in the edge portion and runs parallel to the film, determine the surface area of the joining region.

The invention relates to a reagent reservoir for fluids as part of amicrofluidic flow cell for the analysis and/or synthesis of substancesor as a separate module, comprising a storage chamber connected to achannel for conveying fluid out of, into and/or through the storagechamber, the channel having a channel area which is delimited by asubstrate and by a film connected to the substrate and in which thechannel is closed and can be opened at a predetermined breaking point bydeflection of the film, said film connected to the substrate alsodelimiting the storage chamber in addition to the channel area.

A reagent container of this kind is disclosed in WO 2009/0710781 A1. Thestorage chamber of this known reagent reservoir is formed by athermoformed area of the film which delimits the channel area and isotherwise plane. The film is composed of an aluminum layer with aplastic coating directed toward the inside of the storage chamber.Outside the storage chamber and the channel area, and at thepredetermined breaking point, the film is adhesively bonded and/orwelded to a plane surface of the substrate or of a further film coveringsaid surface.

The surface extent of the predetermined breaking point produced bywelding and/or adhesive bonding between the plastic coating of the filmand the plane surface of the substrate can only be predefined withdifficulty. Variations result especially from the behavior of theplastic coating of the film during welding, the distribution of thetemperature generated by a welding tool, the attainable width of theweld path of ca. 1 mm, the positioning accuracy of the welding tool, andtherefore the reproducibility of the distance of the predeterminedbreaking point from the storage area. Correspondingly, the forced neededto break open the predetermined breaking point also varies undesirably.

The object of the invention is to make available a novel flow cell whichis of the type mentioned at the outset and which has a channel area witha predetermined breaking point, wherein the force for breaking open thepredetermined breaking point lies within a narrow tolerance range.

This object is achieved, according to the invention, in that the filmcovers a recess in the substrate forming the channel area, and a sealingwall that closes the channel and is integrally connected to thesubstrate is arranged in the recess, in that the predetermined breakingpoint is formed by a breakable connection area between the film and anedge portion of the sealing wall directed toward the film, and in thatthe dimensions of an edge surface of the sealing wall formed in the edgeportion and parallel to the film determine the surface extent of theconnection area.

Since the connection area that forms the predetermined breaking point isconcentrated, according to the invention, on the edge surface of thesealing wall that reaches as far as the film, the connection area has adefined recess and position that are independent of the weldingconditions. Variations in the force needed to break open thepredetermined breaking point are correspondingly low.

Said edge surface can be approximated to a line which, for example, runsperpendicularly with respect to the direction of flow of the fluid.

The channel can preferably be opened by fluid pressure bearing on thepredetermined breaking point or by mechanical and/or pneumaticdeflection of the film. Whereas fluid pressure can be built up, forexample, by forcing out a storage chamber with a flexible film wall, anoperating device provided for the flow cell could be used for themechanical and/or pneumatic breaking open of the predetermined breakingpoint.

It will be appreciated that the film on the edge portion can beadhesively bonded and/or welded to the edge surface of the sealing wall.Alternatively or in addition, a releasable clamping connection could beproduced by a clamp element that is connected movably to the flow celland acts on the film.

The sealing wall is preferably formed integrally with the substrate inone work cycle by means of injection molding.

In a particularly preferred embodiment of the invention, the edgesurface of the sealing wall terminates flush with the opening edge ofthe recess formed in the substrate. It is thus possible to ensure that,with its edge portion directed toward the film, the sealing wall reachesas far as the film, and that the film can be adhesively bonded and/orwelded both to the substrate and also to the edge portion of the sealingwall in one work cycle.

While it is possible to configure the sealing wall in a ring shape,blocking off a correspondingly radial flow of fluid of a channel areaforming a through-hole, the sealing wall in the preferred embodiment ofthe invention is configured as a sealing web which is connected at itsends to the substrate and which crosses the recess in the substrate.

The thickness of the sealing wall preferably decreases toward thecovering film, in particular in such a way that the film bears onlylinearly against the edge portion of the sealing wall. This tapering ofthe thickness of the sealing wall not only permits an almost linear edgeportion but also quite a considerable depth of the recess forming thechannel area and, as a result, a low flow resistance during transport ofthe fluid. In addition, this increases the mechanical stability of thesealing wall to forces that act on it during the injection molding andwelding.

Accordingly, the cross section of the sealing wall can, for example,have the shape of a triangle or partial circle.

In a further embodiment, the edge portion of the sealing wall bears witha flattened portion against the film. The length of the flattenedportion in the direction of flow, and therefore the length of thepredetermined breaking point in this direction, is preferably less than0.5 mm, in particular less than 0.1 mm, if appropriate less than 0.05mm. The height of the tapering sealing wall, and therefore of thechannel-forming recess of the substrate, is preferably between 0.1 mmand 1 mm, in particular between 0.2 mm and 0.5 mm.

The recess preferably opens toward a plane surface of a preferablyplate-shaped substrate, and the film covering the recess is preferably aplane film.

In a further embodiment of the invention, the channel, in the channelarea having the predetermined breaking point, is narrowed or widened incross section by comparison with adjoining channel areas. A sealing webcan be correspondingly lengthened or shortened. Since the force forbreaking open the predetermined breaking point depends on the geometryof the connection area between the film and the sealing web, thebreaking-open force can be adapted by suitable choice of the widening ornarrowing. The width of the linear sealing web is preferably between 1mm and 10 mm, in particular between 2 mm and 6 mm. The breaking-openforce applied by a mechanical actuator compressing the storage area ispreferably below 50 N, in particular below 20 N, if appropriate below 10N.

The storage chamber can be formed by a depression in the substrate, by abulge in the film, or both by a depression in the substrate and also adeflection in the film.

Outside the storage area, the film and/or the substrate preferably haveprojections and/or recesses for forming mutual abutments, which permitcontrolled positioning of the film relative to the substrate.

The predetermined breaking point can particularly preferably be brokenopen by deformation of a portion of the film that delimits the storagechamber.

In a particularly preferred embodiment of the invention, the filmdelimits the storage chamber and the channel continuously as far as amouth where the channel opens into a discharging and/or mixing chamber,or as far as a through-hole in the substrate connecting the storagechamber fluidically to the discharging or mixing chamber.

The film is expediently a laminate composed of a metal layer, inparticular an aluminum layer, preferably a soft-annealed aluminum layer,and of a plastic layer, wherein the plastic layer is directed toward thefluid. The laminate can additionally have further layers.

The thickness of the plastic layer is expediently less than or equal tothe width of the edge surface, directed toward the film, of the sealingwall in the longitudinal direction of the channel or the direction offlow. By this measure, the mass of the material to be melted isexpediently kept low, as a result of which the reproducibility of theweld connection increases.

A surface area of the substrate provided for welding to the filmpreferably has a furrowed structure, possibly except for the edgesurface of the sealing wall. The strength of the weld connection betweenthe film and the substrate can be greatly increased by the furrowedstructure. Furrows with widths and heights of between 0.1 mm and 0.5 mmare preferably formed.

In a further embodiment of the invention, the storage chamber, on itsside directed away from the film, has in each case an attachment stubthat can be closed by welding, wherein the attachment stub is preferablyarranged in a depression in a plane bottom surface of the substrate and,in the closed state, is set back in relation to a surface of thesubstrate directed away from the film. The reagent reservoir can thenadvantageously be placed with its bottom surface flush on a planecarrier surface. The internal diameter of the attachment stubs ispreferably in the range of 0.5 mm to 2 mm, and the height of theattachment stubs to be welded is preferably in the range of 0.5 mm to 4mm. The wall thickness of the attachment stubs to be welded ispreferably in a range of 0.5 mm to 2 mm.

In a further embodiment of the invention, the aforementioned dischargingand/or mixing chamber forms a socket for connecting the reagentreservoir to an appliance, in particular to a lateral flow analysischip, in which a functionalized lateral flow membrane, generally usedfor in situ analyses, is enclosed in a plastic housing. The socket ofthe reagent reservoir preferably has positioning and/or fixing elements,such as snap-fit closures or undercuts, which with respect to the mutualposition of the housings of reagent reservoir and analysis chip permit areproducible mechanical connection to the housing of the lateral flowanalysis chip. The position of the lateral flow membrane relative to thedischarge channel of the reagent reservoir is accordingly reproducible,such that the stored fluid, for example a wash buffer, can be broughtinto contact with the lateral flow membrane reproducibly when thestorage area is actuated.

The reagent reservoir according to the invention can also be integratedin such an analysis chip, for example, and can have a housing in commonwith the latter.

In a particularly preferred embodiment of the invention, the substrateis connected to an actuator and/or lid, preferably non-releasably, saidconnection being able to be produced, for example, by a film hinge thatallows the lid or actuator to be folded over in a defined pivotingdirection.

The actuator preferably has a stamp element which can be guided throughan opening in the lid and which deforms the portion of the film formingthe storage chamber; for example, by folding over and/or moving theactuator, the height of the storage chamber can thus be reduced bydeformation of the film, in particular by plastic deformation of thefilm, wherein the stamp element, in an end position of the actuator,preferably completely annuls the height of the storage chamber. In thisway, the storage chamber can be emptied in a reproducible manner.

In the end position, the actuator can expediently be fixed on, inparticular latched onto, the substrate, such that it is possible to tellfrom the fixed position that the reservoir is empty.

The lid can also be expediently fixed on the substrate, in particularclamped and/or latched onto the substrate.

Preferably, the lid together with the substrate forms the abovementioneddischarging and/or mixing chamber.

The reagent reservoir can be combined with a carrier element for a dryreagent, wherein the carrier element with the dry reagent is preferablyprefabricated and, at the time of production of the reagent reservoir,is mounted thereon. For this purpose, in addition to having an area inwhich the dry reagent is applied, the carrier element also has aconnection area preferably integrally connected thereto. The connectionarea can have a screw connection or snap-fit connection. Alternatively,a conical plug area is particularly preferred, e.g. corresponding to theLuer standard, which permits simple mounting of the carrier element on areagent reservoir substrate having a corresponding conical plug area bymeans of an interference fit.

The reagent reservoir can be combined with a carrier element forreceiving a solid or liquid sample to be analyzed, e.g. blood, saliva,stool, a water sample, food, plant samples or soil sample, wherein thesample is preferably applied first to the carrier element, after whichthe carrier element is connected to the reagent reservoir before thelatter is actuated.

In addition to having a receiving area on which a sample volume can beapplied preferably in a reproducible manner, the carrier element has aconnection area that is preferably integrally connected thereto. Theconnection area can comprise a screw connection or snap-fit connection.A conical plug area is preferable, which permits particularly simplemounting of the carrier element on the substrate of the reagentreservoir, in a corresponding conical plug area of the substrate bymeans of an interference fit. Preferably, the sample-receiving area orat least the sample of the carrier element is substantially completelyenclosed by a channel area or chamber area of the reagent reservoir,such that the reagent emerging from the storage chamber into the channelarea can flow over the sample and be washed off from the sample carrier.Alternatively, by comparison with the surface of the sample-receivingarea of the carrier, the channel adjoining the carrier element can havea much smaller channel cross section and, for example, can be routed ina meandering shape over the sample.

The dry reagent and/or the sample can come to be arranged in the channelor in the discharging chamber.

The invention is explained in more detail below on the basis ofillustrative embodiments and with reference to the attached drawingsdepicting these illustrative embodiments, in which drawings:

FIGS. 1 to 3 show a reagent reservoir according to the inventioncomposed of a plastic part and of a laminate film, with mutually movablecomponents in different positions,

FIGS. 4 and 5 show the plastic part of the work reservoir from FIGS. 1to 3 in different perspective views,

FIGS. 6 and 7 show details of possible embodiments of the reagentreservoir from FIGS. 1 to 3, in partial cross sections,

FIGS. 7 and 8 show partial cross sections through reagent reservoirsaccording to the invention, combined with a carrier for a dry reagent,

FIGS. 10 to 13 show partial cross sections through a reagent reservoiraccording to the invention, combined with a carrier for a sample to beanalyzed,

FIG. 14 shows a partial cross section through a reagent reservoiraccording to the invention, integrated in a lateral flow analysis chipfor the analysis of liquids,

FIG. 15 shows a reagent reservoir according to the invention integratedin a lateral flow analysis chip, combined with a carrier for a solidsample to be analyzed, and

FIG. 16 shows a partial cross section through a reagent reservoiraccording to the invention, a lateral flow analysis chip being able tobe inserted into the discharging chamber of said reagent reservoir.

A reagent reservoir shown in FIGS. 1 to 3 comprises a substrate 1produced by injection molding from PMMA, PC, PEEK, PP, PE, COC, PP orother plastics, preferably polyolefins. In the example shown, thesubstrate 1 is connected integrally in each case to a lid 2 and to anactuator 3 via a respective film hinge 4, 5.

The substrate 1 is welded to a film 6. In the example shown, this is alaminate film composed of a soft-annealed aluminum layer and a plasticlayer. A bulge 7 of the film 6 forms a storage space 8 between the film6 and the substrate 1. The film 6 extends past the storage space 8 to anend opening 9 of a channel 10, the latter communicating with the storagespace 8 and opening into a discharging chamber and/or mixing chamber 18of the reagent reservoir.

In the channel 10 formed by a groove in the substrate 1 and covered bythe film 6, a sealing wall 11 is located inside a widening 42 of thegroove (best seen in FIG. 4), and the end edge of the sealing wall 11directed toward the film 6, like the surface of the substrate 1 coveredby the film 6, is welded to the film 6.

The lid 2 has an elongate opening 12 which lies opposite the storagespace 8, when the lid 2 is folded over onto the substrate 1, and whichis adapted to the elongate shape of the storage space 8. The opening 12is surrounded by an annular wall 13 which is produced integrally withthe lid 2 and by which the storage space is enclosed all the way roundwhen the lid 2 is folded over. A transverse wall 14 with niches 15, inwhich seat projections 16 in the substrate 1 engage when the lid 2 isfolded over, ensures, together with a web projection 19, a stableclamped fit of the lid 2 on the substrate 1 and a reproduciblepositioning of the opening 12 relative to the storage space 8.

As can be seen from FIG. 4, which shows the substrate 1 without the film6, a groove 20 is formed in the substrate 1, said groove 20 surroundingthe storage space 8 and further extending along the channel 10. Thegroove 20 ensures a particularly firm weld connection that seals off thestorage space 8 and the channel 10. To improve the weld connection, thesubstrate surface resting against the film 6 additionally has a furrowedstructure (not shown).

As can be seen from FIGS. 4 and 5, two opening channels 22, eachcomprising an attachment stub 21, open into the storage space 8. Theattachment stubs 21 each protrude outward from the bottom of adepression 23. After the storage space 8 has been filled and airremoved, the attachment stubs 21 can be welded in such a way that theirfree ends are set back in relation to the plane bottom surface 24 of thesubstrate 1. Advantageously, the reservoir can thus be placed with itsbottom surface 24 in a stable position on an even support surface.

It will be appreciated that the parts 1 to 3 interconnected by the filmhinges 4, 5 could also be produced as individual parts independent ofeach other.

To withdraw a reagent contained in the storage space 8, the actuator 3can be pivoted through 180°, whereupon a stamp element 17 of theactuator 3 passes through the opening 12 and presses the storage space 8together. As this happens, the weld between the film 6 and the edge ofthe sealing wall 11 tears, which results in the reagent being withdrawnin a controlled flow through the channel 10.

In its end position, the stamp element 17 almost reaches the surface ofthe substrate 1 and is only separated from the latter by the plasticallydeformed film 6.

The emptying of the storage space 8 through plastic deformation of thefilm 6 could also be effected by a stamp that forms part of an operatingappliance.

During the production of the reagent reservoir described above, thesubstrate 1, if appropriate together with the lid 2 and with theactuator 3, is produced in a single manufacturing step, preferably byinjection molding. The production of the shaped film 6 takes place in afurther step. In a third manufacturing stage, the substrate 1 and thefilm 6 are welded to each other, and the storage space 8 and the channel10 are thus formed. Thereafter, the fluid to be stored is introducedthrough the attachment stubs 21 and the openings 22 into the storagespace 8, such that the latter is almost completely filled, preferablyfilled to more than 95% of its storage volume. Finally, the attachmentstubs 21 are welded in order to hermetically seal the storage space suchthat it is stable when stored. The effect of the heat during the weldingis preferably controlled such that the welding procedure is completed inless than 5 seconds, in particular in less than 2 seconds, such thatharmful heating of the stored reagent can be avoided as far as possible.

The reagent reservoir described above can be varied in accordance withthe illustrative embodiments described with reference to FIGS. 6 to 16.

FIG. 6 shows a detail of a reagent reservoir with a substrate 1 and witha lid 2 where, in contrast to the illustrative embodiment in FIGS. 1 to5, a storage space 8 is formed not by a bulge of the film 6 but by adepression 25 in the substrate 1. As in the illustrative embodimentdescribed above, the film 6 is composed of a laminate of an aluminumlayer 26 and of a plastic layer 27. The aluminum layer 26 directed awayfrom the reservoir interior preferably has a thickness of between 10 and150 μm, in particular between 30 and 100 μm. The thickness of theplastic film 27, preferably made from PP or PE, is preferably between 10and 100 μm, in particular between 20 and 50 μm. The plastic material ofthe film 6 and the plastic material of the substrate 1 preferably match.In contrast to the illustrative embodiment shown, a laminate withfurther layers could also be used, or alternatively, in order to formthe storage chamber 8, a single-layer or multi-layer plastic film couldbe used.

FIG. 7 shows the various possibilities for the formation of a storagespace 8. According to FIG. 7a , a storage space 8 is formed by adepression 25 in the substrate 1, as in the illustrative embodiment inFIG. 6. FIG. 7b corresponds to the illustrative embodiment in FIGS. 1 to5, with a storage space 8 formed by a bulge 7 of the film 4. FIG. 7cshows a reagent reservoir with a storage space 8 which is formed both bya depression 25 in the substrate 1 and also by a bulge 7 in the film 6.

Independently of the nature of the formation of the storage space 8, thesealing wall 11 preferably has an end face which is directed toward thefilm 6 and of which the width in the longitudinal direction of thechannel is less than or equal to the thickness of a plastic layer of thefilm 6 welded to it. Advantageously, the volume of material to be meltedduring the welding is thereby reduced and the reproducibility of theweld is improved.

Illustrative embodiments of a reagent reservoir shown in FIG. 8 eachhave a carrier element 28 for receiving dry reagent 29, e.g. a primer, areagent for lysis, or functionalized or magnetic beads, wherein, in thecourse of emptying of the reagent reservoir, a desired further reagentcan be produced, by resuspension and mixing, from the dry reagent andfrom the fluid stored in the storage space 8. According to theillustrative embodiment in FIG. 8, the dry reagent 29 comes to bearranged in the channel 10, such that it is washed off from the carrierelement 28 by the fluid flowing from the storage space 8.

FIG. 9 shows an arrangement of the dry reagent 29 in the dischargingchamber 18. With the chamber 18 in this case serving as mixing chamber,the dry reagent 29 is dissolved by the emerging fluid, e.g. by diffusionand incubation. This dissolution process can be supported by movement ofthe fluid (agitation), by mechanical means (not shown) or by fluidmovements.

Whereas the dry reagent 29 is shown here as being introduced via thecarrier element 28, a dry reagent could also be introduced directly intothe chamber 18 before closure of the lid 2.

Advantageously, the carrier elements 28 with the dry reagent can beprefabricated as separate parts and, in the course of the production ofthe reagent reservoir, can be mounted in a fluid-tight manner by meansof a conical interference fit or by welding.

Reagent reservoirs described in FIGS. 10 and 11 are combined with asample carrier 30 via which a sample 31 to be analyzed, e.g. blood,saliva, urine, tissue, and also plant, food or soil samples, can beintroduced into the reagent reservoir by the user in a convenient mannerand, in particular, in the desired quantity. The sample carrier 30 withthe applied sample 31 can, in accordance with FIG. 10, be fitted on thereagent reservoir in a fluid-tight manner via a plug connection, suchthat the sample 31 is arranged in the channel 10 and is washed round bythe reagent withdrawn from the storage space 8 and at least partiallyresuspended. Preferably, the sample carrier 30 is introduced into thereagent reservoir via a conical closure piece, e.g. corresponding to theLuer standard. The sample 31 washed from the sample carrier 30 by thereagent flowing over it is delivered for further analysis/processingafter leaving the reagent reservoir.

According to FIG. 11, the sample can also be arranged in the dischargingchamber 18, where the sample is dissolved under diffusion and incubationand, if appropriate after mixing with a further fluid, is delivered forprocessing. As in the illustrative embodiment in FIG. 9, the dissolutionprocess can be supported by movement (agitation) of the fluid usingmechanical means or by fluid movement.

FIGS. 12 and 13 show illustrative embodiments with a plate-shaped samplecarrier 32 for receiving a sample 33 to be analyzed. Such samplescarriers, known as “absorband pads”, are preferably made ofnitrocellulose, paper or other porous materials and are generally usedto collect samples of bodily fluids, such as saliva, or in drugs tests.The sample carrier 32 is mounted on the underside of the reagentreservoir, where it delimits a portion 34 of the channel 10 routed onthe underside of the substrate 1. The sample 33 is also washed from thesample carrier 32, by the fluid emerging from the storage space, anddelivered for analysis/processing. In order to maximize the contactsurface between fluid and sample, the channel portion 34 can have ameandering, helical or fork-shaped configuration.

The illustrative embodiment of FIG. 12b differs from the illustrativeembodiment of FIG. 12a in that, in the channel portion 34, needle-shapedelements 35 jut out from the substrate and protrude into the sample 33,thereby enlarging the surface of the area of the sample membrane overwhich the fluid flows and helping to force the sample 33 from the samplecarrier 32.

According to the illustrative embodiment in FIG. 13, a plate-shapedsample carrier 32 with a sample 33 adjoins the discharging chamber ormixing chamber 18.

FIG. 14 concerns a reagent reservoir which has an integrated analysischip 36, working according to the lateral flow principle, and has ahousing in common with the analysis chip 36. A lateral flow membrane 37protrudes into the discharging chamber 18 of the reagent reservoir. Thelateral flow membrane 37 can be wetted with a sample 39, e.g. a bloodsample, through an opening 38. Reagent stored in the storage space 8forms a buffer liquid for the analysis reactions in the lateral flowmembrane.

Costs are reduced by only a single housing being needed for reservoirand analysis chip.

In the illustrative embodiment in FIG. 15, instead of dropping a sampleliquid onto the lateral flow membrane 37, a solid or liquid sample 41 isbrought into contact with a lateral flow membrane 37 by way of a samplecarrier 40. As the reagent withdrawn from the storage space flowsthrough the lateral flow membrane 37, the solid sample 41 is flushed offand caused to react.

FIG. 16 shows an illustrative embodiment in which a separate lateralflow analysis module 43 with a lateral flow membrane 37 can be insertedinto the discharging chamber 18 of a reagent reservoir.

1-15. (canceled)
 16. A reagent reservoir for fluids as part of amicrofluidic flow cell or as a separate module, comprising: a channel; astorage chamber connected to the channel for conveying fluid out of,into and/or through the storage chamber, the channel haying a channelarea delimited by a substrate and by a film connected to the substrateand in which the channel is closed and openable at a predeterminedbreaking point by deflection of the film, the film connected to thesubstrate also delimiting the storage chamber in addition to the channelarea, wherein the film covers a recess in the substrate forming thechannel area; and a sealing wall is arranged in the recess to close thechannel, the sealing wall being integrally connected to the substrate,wherein the predetermined breaking point is formed by a breakableconnection area between the film and an edge portion of the sealing walldirected toward the film, an edge surface of the sealing wall formed inthe edge portion and parallel to the film has dimensions that determinea surface extent of the connection area.
 17. The reagent reservoiraccording to claim 16, wherein the storage chamber is formed by adepression in the substrate, by a bulge of the film, or by both adepression in the substrate and a bulge in the film,
 18. The reagentreservoir according to claim 16, wherein the predetermined breakingpoint is breakable by deformation of a portion of the film delimitingthe storage chamber, wherein the film delimits the storage chamber andthe channel continuously as far as a mouth where the channel opens intoa discharging and/or mixing chamber.
 19. The reagent reservoir accordingto claim 16, wherein the film is a laminate composed of a metal layerand at least one plastic layer, wherein the plastic layer is directedtoward the fluid, wherein the plastic layer has a thickness less than orequal to a width of the edge surface, directed toward the film, of thesealing wall in a longitudinal direction of the channel.
 20. The reagentreservoir according to claim 19, wherein the metal layer is an aluminumlayer.
 21. The reagent reservoir according to claim 20, wherein thealuminum layer is a soft-annealed aluminum layer.
 22. The reagentreservoir according to claim 16, wherein the substrate has a surfacearea provided for welding to the film, the surface area having afurrowed structure, except for the edge surface of the sealing wall, 23.The reagent reservoir according to claim 16, wherein the storagechamber, on a side directed away from the film, has opening channelswith in each case an attachment stub that is closeable by welding,wherein the attachment stub is arranged in a depression in the substrateand, in a closed state, is set back in relation to a surface of thesubstrate directed away from the film.
 24. The reagent reservoiraccording to claim 18, wherein the discharging and/or mixing chamberforms a socket for connecting the reagent reservoir to an appliance. 25.The reagent reservoir according to claim 18, wherein the substrate isconnected to an actuator and/or a lid.
 26. The reagent reservoiraccording to claim 25, wherein the actuator and/or the lid is connectedto the substrate non-releasably and pivotably.
 27. The reagent reservoiraccording to claim 26, wherein the actuator and/or the lid is connectedto the substrate by a film hinge.
 28. The reagent reservoir according toclaim 25, wherein the actuator comprises a stamp element guided throughan opening in the lid and deforms the portion of the film, and the stampelement, in an end position of the actuator annuls a height of thestorage chamber by the deformation.
 29. The reagent reservoir accordingto claim 25, wherein the lid and/or the actuator, in a end position, arefixable on the substrate and, optionally, the actuator is fixable on thelid.
 30. The reagent reservoir according to claim 29, wherein theactuator is damped and/or latched onto the substrate or lid.
 31. Thereagent reservoir according to claim 25, wherein the lid together withthe substrate forms the discharging and/or mixing chamber.
 32. Thereagent reservoir according to claim 18, wherein the reagent reservoiris connectable to a carrier element for a dry reagent or a sample, andthe dry reagent and/or the sample is arranged in the channel or thedischarging chamber by the carrier element.
 33. A method for producing areagent reservoir according to claim 16, comprising forming a storagechamber, an emptying channel connected fluidically to the storagechamber, and a predetermined breaking point closing the emptying channelbetween a substrate and a film in a single work cycle in which thesubstrate is welded to a film that has been cut to size.
 34. The methodaccording to claim 33, including introducing a reagent into the reagentreservoir so that the reagent fills the storage volume of the reagentreservoir by more than 90%.
 35. The method according to claim 34,wherein the reagent fills the storage volume of the reagent reservoir bymore than 95%.
 36. The method according to claim 34, wherein, after thereagent reservoir has been filled with a reagent, attachment stubsconnected to the storage chamber are closed by welding, wherein thewelding lasts not more than 5 seconds.
 37. The method according to claim36, wherein the welding lasts not more than 2 seconds.